Double connector for medical sensor

ABSTRACT

A double electrode connector for connecting to medical electrodes preferably in an impedance cardiography system includes a connector housing comprising a base having two holes therein of predetermined diameters arranged at predetermined location in the housing, with a first of the two holes associated with a first connector and a second of the two holes associated with a second connector of the double-electrode connector; a pair of biasing elements arranged along a surface of the housing so that each one of the pair of biasing elements is adapted for biasing against an electrode stud inserted in a respective hole of the two holes in the housing; a cable assembly including a twin wire cable and a bend relief, wherein each one of the pair of metal lugs is connected to one of the first connector and second connector, and the bend relief is arranged in a hole in the base to flexibly connect the twin wire cable to respective metal lugs of the pair of metal lugs. The biasing means may include handles to assist with attaching the double connector to two electrodes with a near-zero insertion force towards a patient.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional application Ser.No. 60/435,246 filed Dec. 20, 2002, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to improved electrical clasp structuresfor transferring electrical signals to a medical electrode. Moreparticularly, the present invention relates to a double connector forimpedance cardiography.

2. Description of the Related Art

Impedance cardiography (ICG) is a medical test to determine the pumpingcapacity of the heart. ICG is a non-invasive and cost-effectivetechnique for determining stroke volume (SV), cardiac output (CO), andthoracic fluid volume (TFC, or ZO). Impedance cardiography is alsoreferred to as “Non-Invasive Continuous Cardiac Output” (NiCCO), whichrequires four pairs of electrodes to perform the testing.

In prior art systems, such as, for example the IQ System (WantaghIncorporated, Bristol, Pa.) an operator places eight ICG electrodes(four sets of two) and three ECG electrodes on the patient. In the caseof thoracic electrical bioimpedance, the amount of resistance that anelectrical current meets is measured as it travels through the thorax.In such systems, there is one connector per electrode.

Other devices exist in the field of electrocardiography (ECG or EKG)that also have one connector per electrode, such as disclosed in U.S.Pat. Nos. 5,944,562 and 5,295,872, both to Christensson.

To date, there is a double electrode being used for impedancecardiography by CardioDynamics of San Diego, Calif. This cable has eightbranches and uses two connectors for each double electrode. However, theuse of two connectors for each double electrode still requires eightindividual connections to these electrodes.

SUMMARY OF THE INVENTION

The present invention provides a zero-insertion force (ZIF) connectorthat easily connects a two-conductor cable to a medical electrode ormedical sensor having two connections. According to an aspect of theinvention, the medical electrode or sensor can be disposable, and mayinclude a snap stud connection so the connector attaches with Zeroinsertion force onto a stud. According to an aspect of the invention,the zero insertion force permits the connector to be attached to theelectrode or sensor after the electrode has been positioned on thepatient without discomfort.

According to another aspect of the invention, the connector can bepolarized to properly attach to the double electrode. The invention alsopermits the connections to be made faster (only four instead of eight),and reduces the number of branches. In addition, a double connectorprevents the substitution of standard (single) ECG electrodes that wouldintroduce variability in the impedance cardiography test results.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a perspective view of a double connector accordingto the present invention.

FIG. 1B illustrates another view of the double connector, shown withouta cover for more clarity.

FIG. 1C is a rear view of the double connector with the cover on.

FIG. 1D is an exploded view of some of the components shown in FIGS. 1Aand 1B.

FIG. 2 shows the connector being applied to a medical sensor.

DETAILED DESCRIPTION OF THE INVENTION

It is understood by persons of ordinary skill in the art that theillustrations and description herein are provided for purposes ofexplanation, and the claimed invention is not limited to the embodimentsshown and described, as an artisan can make variations in the designthat lie within the spirit of the invention and the scope of theappended claims.

According to an aspect of the invention shown in FIGS. 1A and 1B, adouble connector includes a housing comprising a base 1 and cover 2. Thebase is preferably constructed of injection-molded plastic, but suitablesubstitutes can be used. The base has two holes 12, 13 (shown in FIG.1B), with the smaller hole 12 permitting only a smaller stud of a doublesensor (Item 15, FIG. 2) to pass but preventing a larger stud (e.g.,item 14, FIG. 2) from entering.

As best shown in FIG. 1D, there are two electrical contacts 3 which fitinto respective recesses of handles 4. In this particular case, theelectrical contacts 3 may serve as leaf springs in and of themselves,but additional contact force can be provided by a coil spring (notshown). The handles 4 have a cylindrical feature 4A at one end, allowingthem to rotate within the housing and protrude from the cover 2 at theother end. At least one contact/tab 3A on each spring is positioned tocatch the groove of the snap stud 14, 15. The springs may have two tabs,so that a single spring design could be used as either of the twobiasing devices. The handles and/or the bend relief can be color codedto facilitate an accurate connection to the electrodes.

As shown in FIG. 1B, a cable assembly 5, which is preferably molded,comprises twin-wire cable 6 (preferably coaxial cable for low noise),and a bend relief 7, which is also preferably molded. The bend reliefpreferably fits in a hole in the base 1, and should include a flatsection to insure proper orientation. The bend relief can be molded indifferent colors to identify individual connectors.

Prior to final assembly, the conductors of each coaxial wire 6 a and 6 bare exposed and attached to the respective spring-contact, preferably bycrimping into cylindrical feature 3B, but other methods may be used.

The base 1 prevents unwanted motion of the parts and keeps wire strandsof one conductor from shorting to the other conductor. It is preferablethat the base 1 and cover 2 permanently attach by a snap-fit, adhesive,or ultrasonic weld, although it is possible to make the coverdetachable. The cover 2 may optionally include icons to identify properlocations for each connector in the cable harness. Two knobs 10 can bemolded onto the cover 2 to simulate the two snap studs of an electrode,allowing one double connector to be attached to another for convenientand neat storage.

In order to install the double connector, an operator squeezes the twohandles 4 together, places the connector over the two studs of theelectrode, and releases the handles. A tab 3A on each spring catches inthe groove of the respective snap stud of the electrode 13, 14, holdingit in place. To remove, the process is reversed. Thus, as the doubleconnector can be connected/disconnected with zero insertion force, thereis an advantage in that patient discomfort is reduced as compared to theuse of conventional snap studs where there can be bias force appliedtoward the patient.

FIG. 2 shows a double connector according to the present invention beingapplied to the medical sensor. It is to be understood that theproportions are not limitations of the double connector, but are merelyincluded for illustrative purposes.

Some of the many features of the present invention include:

(1) with zero insertion force (meaning the biasing is removable bysqueezing the levers), the connector can be attached to the electrodeafter the double electrode has been positioned on the patient, therebyreducing or eliminating discomfort that would occur with a standard snapfitting or other connector;

(2) the connector can be polarized (by different size holes) to preventinadvertent interchange of electrodes;

(3) combining two connections in one operation increases the speed withwhich the connectors can be installed on a patient, and provides moreconvenience to the practitioner;

(4) reducing the number of branches in the harness from eight to four,reducing the likelihood of tanglement and identification time in priorart devices containing eight branches;

(5) reducing the tendency of capacitance of the two wires to change andcreate electrical noise by securing the two wires to each other, whichwould not be possible in a single electrode connector;

(6) a double connector reduces the possibility that standard ECGelectrodes would be substituted for (false) economy, so that resultswould be unnecessarily variable;

(7) the double connector is large enough to have one or more identifyingicons arrange thereon;

(8) the design has features that permit color-coding the individualconnections;

(9) the design can fit within the electrode profile without overhang,reducing discomfort to the patient from contact by hard edges, andreducing the provider's need to touch the patient's skin; and

(10) self-storage knobs that simulate electrodes permit the connectorsto be clipped together when not in use.

There are many modifications that may be made by a person of ordinaryskill in the art that would be within the spirit of the invention andthe scope of the appended claims. For example, the shape of the housing,the positioning of the holes and/or the shape of the holes to receivethe electrodes, and the particular sizes of the elements could be variedaccording to specific needs. For example, the holes could be slots,ovals, square, polygonal, etc., so long as they properly receive theelectrodes. It is also noted that while the double connector is suitedfor connection with the previously mentioned double-electrodes, it ispossible that the connector could also be suited for use with singleelectrode medical systems.

1. A double electrode connector comprising: a double-electrode connector housing comprising a base having two holes therein of predetermined diameters arranged at predetermined locations in the housing, with a first of the two holes associated with a first connector and a second of the two holes associated with a second connector of the double-electrode connector; a pair of manually adjustable biasing elements arranged along a surface of the housing so that each one of the pair of biasing elements is adapted for biasing against one of a pair of electrode studs when the studs are inserted in a respective hole of the two holes in the housing; and a two-wire cable, and a pair of metal contacts, electrically connected to the biasing elements, wherein each one of the pair of metal contacts is coupled to one of a first conductor and second conductor of the two-wire cable.
 2. A double electrode connector comprising: a double-electrode connector housing comprising a base having two holes therein of predetermined diameters arranged at predetermined locations in the housing, with a first of the two holes associated with a first connector and a second of the two holes associated with a second connector of the double-electrode connector; a pair of biasing elements arranged along a surface of the housing so that each one of the pair of biasing elements is adapted for biasing against one of a pair of electrode studs when the studs are inserted in a respective hole of the two holes in the housing; and a two-wire cable, and a pair of metal contacts, wherein each one of the pair of metal contacts is coupled to one of a first conductor and second conductor of the two-wire cable, wherein the first connector and the second connector connect to the respective one of the pair of electrode studs with zero insertion force.
 3. The double connector according to claim 1, wherein each of the biasing elements comprises a tab adapted to bias against a respective electrode stud of the pair of electrode studs.
 4. A double electrode connector comprising: a double-electrode connector housing comprising a base having two holes therein of predetermined diameters arranged at predetermined locations in the housing, with a first of the two holes associated with a first connector and a second of the two holes associated with a second connector of the double-electrode connector; a pair of biasing elements arranged along a surface of the housing so that each one of the pair of biasing elements is adapted for biasing against one of a pair of electrode studs when the studs are inserted in a respective hole of the two holes in the housing; and a two-wire cable, and a pair of metal contacts, wherein each one of the pair of metal contacts is coupled to one of a first conductor and second conductor of the two-wire cable, wherein each of the biasing elements comprises a tab adapted to bias against a respective electrode stud of the pair of electrode studs, wherein the biasing elements comprise leaf springs, and each of the biasing elements further comprises a handle attached to the leaf spring that protrudes out of the connector housing.
 5. The double connector according to claim 4, wherein at least one of one the handles and a bend relief is color-coded for connection to specific electrodes.
 6. The double connector according to claim 1, wherein the case housing includes a cover and a base, and both are comprised of injection-molded plastic.
 7. The double connector according to claim 1, wherein the predetermined diameters of the two holes formed in the base are sized such that one of the two holes is smaller than the other of the two holes.
 8. The double connector according to claim 1, wherein the predetermined diameters of the two holes are sized to correspond with a diameter of at least one of the electrode studs.
 9. The double connector according to claim 4, wherein each of the biasing elements includes two or more tabs arranged opposite to each other.
 10. The double connector according to claim 4, wherein in a first position the handle is arranged so to as to permit an electrode stud to be inserted in one of the two holes in the base.
 11. The double connector according to claim 10, wherein in a second position, the handle is arranged so as to bias the leaf spring 3 against the electrode stud inserted in one of the two holes in the base.
 12. The double connector according to claim 1, A double electrode connector comprising: a double-electrode connector housing comprising a base having two holes therein of predetermined diameters arranged at predetermined locations in the housing, with a first of the two holes associated with a first connector and a second of the two holes associated with a second connector of the double-electrode connector; a pair of biasing elements arranged along a surface of the housing so that each one of the pair of biasing elements is adapted for biasing against one of a pair of electrode studs when the studs are inserted in a respective hole of the two holes in the housing; and a two-wire cable, and a pair of metal contacts, wherein each one of the pair of metal contacts is coupled to one of a first conductor and second conductor of the two-wire cable, further comprising self-storage knobs that protrude in alignment with the two holes in the base to allow attachment to another double connector.
 13. The double connector according to claim 1, wherein the connector housing has at least one icon arranged thereon to facilitate a connection with a double electrode.
 14. The double connector according to claim 11, wherein the first position of the handle, the leaf spring provides no insertion force downward toward a patient's neck and/or torso.
 15. The double connector according to claim 11, wherein in a second position of the handle, the leaf spring provides a biasing force tangential to the neck and/or torso of a patient.
 16. The double connector according to claim 4, wherein the housing has two pairs of recesses that each retain an end of one of the respective handles while allowing the handle to pivot.
 17. A method of making a double electrode connector, connecting the steps of: (a) providing a connector housing comprising a base having two holes therein of predetermined diameters arranged at predetermined locations in the housing, with a first of the two holes associated with a first connector and a second of the two holes associated with a second connector of the double-electrode connector; (b) arranging a pair of biasing elements along a surface of the housing so that each one of the pair of biasing elements is adapted for biasing against an electrode stud inserted in a respective hole of the two holes in the housing; (c) providing a two wire cable, a pair of metal contacts, and connecting each one of the pair of metal contacts to one of the first conductor wire and second conductor wire, and a bend relief connecting the two wire cable to the housing of the case assembly; and (d) providing a manual control for simultaneously biasing the pair of biasing elements away from the electrode studs inserted in the holes.
 18. The method according to claim 17, A method of making a double electrode connector, connecting the steps of: (a) providing a connector housing comprising a base having two holes therein of predetermined diameters arranged at predetermined locations in the housing, with a first of the two holes associated with a first connector and a second of the two holes associated with a second connector of the double-electrode connector; (b) arranging a pair of biasing elements along a surface of the housing so that each one of the pair of biasing elements is adapted for biasing against an electrode stud inserted in a respective hole of the two holes in the housing; (c) providing a two wire cable, a pair of metal contacts, and connecting each one of the pair of metal contacts to one of the first conductor wire and second conductor wire, and a bend relief connecting the two wire cable to the housing of the case assembly; wherein the first connector and the second connector connect to the electrode studs with zero-insertion-force.
 19. The method according to claim 17, wherein the first connector and the second connector connect to the electrode studs by snapping on. 